Security experts have criticised new rules which mean bank fraud victims no longer report the crime to the police.

Under the new Fraud Act, from 1 April consumers will have to notify their bank directly of any suspicious transactions.

The bank will then decide whether to pass the details onto law enforcement agencies.

Experts fear this gives too much discretion to the banks over what types of fraud are reported and investigated.

Professor Ross Anderson of Cambridge University's Computer Lab said he believes the government is only introducing the change because it will cut down on recorded crime figures as the banks will not report all the fraud they encounter.

And he argued the banks also have an ulterior motive in making the change: "The banks think it's great because it gives them control over which frauds are investigated."

"For bank customers it's a disaster. If you're the victim of a bank fraud whose existence the bank doesn't want to acknowledge, you're left with nowhere to turn."

Andrew Goodwill, managing director of internet security company Early Warning is also concerned.

"The police have already told me they will only be looking to investigate the large crimes," he told the programme.

"It sends a message to the fraudsters that they will be able to commit crime with very little or no chance of being caught as the police won't investigate them."

Accurate figures

The new legislation follows discussions between the Home Office, the Police and the banks.

Industry figures show that there were just over 700,000 cases of card fraud in 2006, with the average loss per case amounting to £608.

Sandra Quinn of Apacs, which represents the credit and debit card industry, has defended the changes.

She believes they will reduce bureaucracy and provide more accurate figures.

"There has been mass under-reporting in the past by the police," she said.

"This change simply removes an additional level of reporting and will provide greater consistency for the reporting of fraud losses in the UK."

The Home Office said it is a matter for individual police forces which crimes they allocate resources to investigate.

Where an additional crime has been committed with the fraud, for example, the victim has had their wallet stolen, or the card used fraudulently was stolen as a result of a burglary, then this should still be reported to the police.

It added that non banking fraud will be dealt with by the police in the same way as it is currently.

BBC Radio 4's Money Box was broadcast on Saturday, 31 March 2007 at 1204 GMT.